The use of volumetric pumps to assist in the infusion of medications to patients is well established in the medical field. Several devices have been proposed for this purpose. For example, U.S. Pat. No. 3,985,133, which issued to Jenkins, claims and discloses a volumetric pump that accurately infuses medications to a patient. As another example, U.S. Pat. No. 4,617,014 to Cannon discloses a linear peristaltic pump which also accurately infuses medications to a patient. Such systems, however, are typically designed for the infusion of medications through a single fluid line. Thus, whenever an additional medical fluid needs to be infused, either the pump must be temporarily shut down while the fluid container in the existing IV system is changed or a separate IV system must be set up. In either case, there may be unacceptable delays. Moreover, additional IV lines may need to be inserted into the patient, causing patient discomfort and compounding the problems associated with IV line management and maintenance. Such problems, however, can be avoided if the new medical fluid can be introduced into the existing fluid delivery system without disassembling the existing system.
Several valving devices have been proposed in the prior art for diverting fluid flow from one path to another. One such valve is the manually-operable three-way valve device disclosed in U.S. Pat. No. 3,057,370 to Hamilton. Other valves, such as the check valve disclosed in U.S. Pat. No. 3,352,531 to Kilmark have been proposed which are opened by cooperation with an external structure, such as the tip of a syringe, to establish a fluid passageway. Additional examples of such devices in the medical field are U.S. Pat. No. 3,385,301 to Harautuneian and U.S. Pat. No. 3,799,171 to Patel. Another depressor activated device is the valve disclosed in U.S. Pat. No. 3,965,910 to Fischer which defines a separate passageway for the addition of a second fluid into an existing fluid pathway during engagement of the depressor. Further, these are numerous examples of so-called piggy back systems which allow for the continuity of infusion from two separate fluid sources. The device disclosed in U.S. Pat. No. 4,533,347 to Deckert and assigned to the same assignee as the present invention is an example of one such system. There is, however, still the need for continuity of infusion from more than one secondary source. Also, there is a need for an automatic return to the normal fluid flow of the pre-existing fluid pathway when flow from several fluid sources has been completed.
Accordingly, it is an object of the present invention to provide a multiline check valve which is simple in operation and allows for easy engagement of a plurality of secondary fluid sources into a pre-existing fluid flow line. Another object of the present invention is to provide a cost effective disposable valve for use with a pumping system that will permit the accurate delivery of fluid from a plurality of separate fluid sources. It is still another object of the present invention to provide a valve which can re-establish the pre-existing fluid pathway after the introducation of fluid from the second sources has been completed.